[cookbook] Add configurable Docker build arguments

[williamw]

Summary

• Refactored Dockerfile to support flexible base image selection via build arguments
• Added MAX_GPU and MAX_TAG build arguments for customizable container builds
• Updated to MAX nightly images with universal GPU support by default
• Documented build arguments in README with examples

Changes

Dockerfile

• Implemented multi-stage build pattern to support multiple MAX base images
• Added MAX_GPU build arg (default: universal) to select between:
  • universal → modular/max-full (larger, all GPU types)
  • amd → modular/max-amd (smaller, AMD-specific)
  • nvidia → modular/max-nvidia-full (smaller, NVIDIA-specific)
• Added MAX_TAG build arg (default: latest) to select image version
• Updated to Node.js 22.x
• Cleaned up Dockerfile structure with comments

README.md

• Added "Build Arguments" section documenting MAX_GPU and MAX_TAG
• Provided examples for building AMD and NVIDIA-specific containers
• Updated Docker instructions to reflect universal base image default
• Fixed example model references to use mistral-community/pixtral-12b

Other

• Fixed JSON formatting in .sample.env
• Updated ecosystem.config.js to support legacy MAX health check URL and CLI arguments

Benefits

• Smaller containers: Users can build GPU-specific images to reduce container size
• Flexibility: Support for different MAX versions via MAX_TAG
• Compatibility: Universal image works with all GPU types by default

Test Plan

• Validated max-nvidia-full:nightly works as base container
• Validated max-amd:nightly works as base container
• Validated max-full:latest works as base container
• Verified multi-stage build only downloads selected base image

🤖 Generated with Claude Code